In underground mining, it has long been known to improve the mining capacity of an extraction system for mineral extraction by virtue of the fact that the interface between floor rock and the mineral to be won, for example coal, is scanned by means of suitable sensor systems, in order to mine with the hewing tools of the extraction system, as far as possible, solely minerals at the floor. The known sensor systems consist almost exclusively of optical sensor systems, which, by means of suitable pressure elements (springs), are pressed against the floor in order to scan the optically different reflectivity of coal, on the one hand, and floor rock, on the other hand. Purely by way of example, reference is made to DE 199 25 949 A1, in which an optical sensor system, as a complex exchangeable part, is disposed in a vertically movable manner in a retaining box, which is fastened by means of push bolts in a recess on the front side of the machine frame of a coal plough and is open downward to the floor. In the coal plough of the generic type, above the sensor device, there is arranged a roof tool, with which the mining height of the extraction system can be changed. The known optical sensor system, by dint of its design, can scan the interface solely in the region of the floor.
According to the invention of this application, provided is an extraction system which can be provided or used with an improved sensor system.
More particularly, this is achieved according to the invention by the fact that a retaining box for the sensor system is fastened in projecting arrangement to the front side of the machine frame, the retaining box preferably containing a georadar as the sensor system. As a result of the projecting fastening of the retaining box, it is not only possible to be able to use other sensor systems, such as, in particular, a georadar, but, at the same time, the precondition is created that the entire working face, and not just the interface between the floor and the minerals to be extracted, can be scanned. The projecting fastening allows a direct, substantially optimal “view” of the working face, the working face being able to be scanned with the sensor system throughout the region lying, on the front side or working side, in front of a machine track on the conveyor, to in front of the canopy end of the canopy of a shield support.
In the preferred embodiment, the georadar and/or the retaining box are arranged centrally between the hewing tools. The number and angle of radiation of the sensors can be used to determine over what region of the working face a scanning of the interface between minerals and host rock should take place, while all sensors can be disposed in a protected manner in the reception space of the retaining box. A georadar is fundamentally suitable for use on both ploughing-type extraction systems and cutting-type extraction systems. A principal field of application of the present invention concerns extraction systems, however, in which the hewing tools consist of cutting rollers, i.e. in particular shearer loaders for coal extraction.
For numerous applications, it may be sufficient to fit the retaining box in a fixed position on the front side of the machine frame. In the case of height-adjustable hewing tools, in particular of height-adjustable hewing tools on the respectively leading front side of the extraction system, it can be advantageous, however, if the retaining box is height-adjustable or is fastenable in different height positions to the machine frame.
In the particularly preferred embodiment, the retaining box is of multipart construction and has a main box accommodating the georadar and having downward and/or upward facing window openings, to both sides of which main box deflector elements are arranged. The retaining box can then be constructed as a closed retaining box, from which only the signal and supply lines for the sensor system have to be led, preferably on the rear side, while the two deflector elements serve to protect the main box and lead fragmented rock or debris past the main box.
The aforesaid can be achieved in a retaining device for a sensor system by the fact that the retaining device utilizes a multipart retaining box for a georadar and can be detachably fastened in projecting arrangement to a front side of a machine frame of the extraction system. The retaining box here preferably has a main box accommodating the georadar and having downward and/or upward facing window openings, and further has deflector elements, which can be arranged to both sides of the retaining box.
Expediently, the window openings are configured in a roof wall and/or a bottom wall of the main box, which respectively run obliquely to a rear wall of the main box, to enable the working face to be scanned in the region of the floor and, where necessary, also in the region of the roof, with the sensors of the georadar, which sensors are disposed in the main box. The windows are preferably closed off by means of exchangeable viewing plates, in particular plastics sheets, for the georadar, in order that, on the one hand, the electromagnetic waves of the sensors of the georadar can scan the working face and, at the same time, the radiated waves can be received by means of the sensors with least possible obstruction. In the event of excessive wearing of the viewing plates, these can be exchanged for new viewing plates.
In the particularly preferred embodiment, the main box is elongated in configuration and/or is closed off by means of trapezoidal side walls and a rectangular end plate. As a result of the trapezoidal shape of the retaining box, a relatively low resistance to debris or the like is achieved, while also, at the same time, a diversion function is maintained in the region of the main box. Advantageously, the deflector elements consist of a back plate, a plurality of stiffening ribs and a trapezoidal connecting wall, which are welded together to form a stable welded construction. The upper and the lower stiffening rib of the deflector elements preferably run obliquely to the back plate and, in particular, in alignment with the bottom wall and the roof wall on the main box. When minerals are to be won, should the diversion function not be fully achievable with correspondingly simply constructed deflector elements, each deflector element can additionally be fitted with a suitable cutter bar in order, where necessary, with the, in the direction of travel, leading cutter bar, to cut away material which has stayed behind the hewing tools in the direction of travel. Each deflector element can also be fitted with a wear plate as additional wear protection, or can have a surface layer hardening.
Also preferably, the rear wall can protrude beyond the roof wall and bottom wall, or the back plate can protrude beyond the upper and the lower stiffening plate, in the upward and downward direction, with a screw hole punched strip, in order that the machine box can be fastened relatively easily in projecting arrangement to the machine frame. In the fitted state of the retaining box on the extraction system, the holes of the screw hole punched strip are passed through preferably by clamping screws, which, where necessary together with dowel pins, serve to absorb the longitudinal and transverse forces and, at the same time, form predetermined breaking points between the machine frame, on the one hand, and the retaining box, on the other hand.
These and other objects, aspects, features, developments, embodiments and advantages of the invention of this application will become apparent to those skilled in the art upon a reading of the Detailed Description of Embodiments set forth below taken together with the drawings which will be described in the next section.